If the FPS rate of the game is higher than the monitor's refresh rate, some of the rendered frames are never shown and the time and processing power used rendering them is wasted.
Upgrading your GPU to get 100 fps on your cheap LCD screen is somewhat like buying $10,000 speakers without silencing the giant air conditioning unit outside your window. If you want to go past 60 fps, you should make sure your display supports high refresh rates.

a kludne ti to tam moze pisat aj 300 fps.